Proteoglycans carrying one or more glycosaminoglycan (GAG) chains form a large gene family that may be classified into five groups according to the structural properties of the core protein. One of the groups is the small Leucine-rich proteoglycan family comprised of decorin (DCN), biglycan, fibromodulin and lumican. These are characterized by 40 kDa core proteins that contain Leucine-rich repeats of approximately 12 amino acids. DCN is a prototype of the group and is also referred to as PG-S2, PG40, proteodermatan sulphate and DS-PGII. It contains one dermatan chondroitin sulphate GAG chain covalently linked to a Serine of the mature core protein and is considered to be a multifunctional proteoglycan.
Decorin protein is present in most all animal tissues. The reduction or absence of decorin leads to problems within the body. The proposed functions of DCN include, but are not limited to, regulation of collagen fibrillogenesis, maintenance of tissue integrity via binding with fibronectin and thrombospondin, and a reservoir of transforming growth factor β (TGF-β). The latter function of DCN is achieved through its core protein sequestering the growth factor in the extracellular milieu from receptors expressed on the cell surface. Various conditions including all types of surgery, cuts, burns, eye injuries, spinal cord injury, head trauma, lung disease, kidney disease, liver disease and cancer can disrupt the balance of decorin in the effected tissue.
Therapeutic use of decorin in humans has been proposed. Examples of such uses include: suppression of cell proliferation by decorin (U.S. Pat. No. 6,046,162); methods for inhibiting TGF-beta activity (U.S. Pat. No. 6,277,812); methods of a pathology or a fibrotic condition by administering decorin (U.S. Pat. No. 6,436,900); methods of preventing or reducing scarring with decorin or biglycan (U.S. Pat. No. 6,509,314), treatment of glomerulonephritis with decorin (U.S. Pat. No. 5,726,149); suppressing tumor cell growth by administering decorin (U.S. Pat. No. 6,524,573); and inhibiting proliferative diseases by inhibiting TGF-beta mediated angiogenesis (U.S. Pat. No. 6,673,341). All of the patents referenced in this paragraph are incorporated herein by reference in their entirety.
What is needed in the art are decorin compositions for use in veterinary therapies.